β-D-Glucan from barley is widely used in the food and pharmaceutical industries due to its functional and health-promoting properties. It acts as a soluble dietary fiber that helps reduce blood cholesterol levels, making it a key ingredient in heart-healthy food products such as fortified cereals, breads, and beverages. Its viscosity and water-holding capacity improve texture and shelf life in baked goods and processed foods. In nutraceuticals, it is valued for its immune-modulating effects, supporting the body’s defense mechanisms by activating immune cells. Additionally, β-D-glucan is used in cosmetic formulations for its skin-hydrating and anti-aging properties, providing a natural moisturizing effect in creams and lotions. Its gelling and stabilizing abilities also make it useful in drug delivery systems, where it helps control the release of active ingredients.